Can't set static IPs

[alex_laco]

Hey guys,

I have a slight, specific problem with my OpenVPN server. I'm running the OpenVPN server on Ubuntu 22.04. The basic setup works very well, clients connect, and the server is okay.

My plan is to configure the server for different subnets like "10.8.0.x" for the server, "10.8.1.x" for clients, and "10.8.2.x" for devices.

But the problem starts when I try to set a static IP for each client. I followed the steps on various internet forums.

The client successfully connects, but I can't even ping the server (10.8.0.1). However, when I delete the "/etc/openvpn/ccd/client1" file, I get a normal "random" IP, and everything works fine. After that, I can normally ping the server.

Where could the problem be in my server setup? I've opened every port and enabled port forwarding.

Thank you

Here are some confs and log from server.

I create client name file in "/etc/openvpn/ccd/client" with code:

ifconfig-push 10.8.1.5 192.168.1.6
iroute 10.8.1.0 255.255.255.0

And then this is my server.conf

port 1194
proto udp
dev tun
ca ca.crt
cert amicus-vpn.crt
key amicus-vpn.key
dh dh.pem
topology subnet
server 10.8.0.0 255.255.252.0
ifconfig-pool-persist var/log/openvpn/ipp.txt
client-config-dir ccd
push "route 10.8.0.0 255.255.255.0"
push "route 10.8.1.0 255.255.255.0"
route 10.8.0.0 255.255.255.0
route 10.8.1.0 255.255.255.0
keepalive 10 120
tls-auth ta.key 0
cipher AES-128-GCM
data-ciphers AES-128-GCM
auth SHA256
persist-key
persist-tun
verb 3
explicit-exit-notify 1

And this is my client config:

client
dev tun
proto udp
remote xxx.xxx.xxx.xxx 1194
resolv-retry infinite
nobind
persist-key
persist-tun
ca ca.crt
cert client.crt
key client.key
remote-cert-tls server
tls-auth ta.key 1
cipher AES-128-GCM
data-ciphers AES-128-GCM
auth SHA256
verb 3

<ca>
-----BEGIN CERTIFICATE-----
x
-----END CERTIFICATE-----
</ca>

<cert>
-----BEGIN CERTIFICATE-----
x
-----END CERTIFICATE-----
</cert>

<key>
-----BEGIN PRIVATE KEY-----
x
-----END PRIVATE KEY-----
</key>

<tls-auth>
-----BEGIN OpenVPN Static key V1-----
x
-----END OpenVPN Static key V1-----
</tls-auth>

This is log from server when I start it and connect user
Link because its too long for post

https://pastebin.com/psxCS6Ur

[RemoteOne]

You can use the option for persistent IPs to record/re-assign the same IP to clients. It doesn't necessarily allow you to pre-assign the IPs - but it will keep them consistent. Having said that, if you pre-populate the file before the first client connection, you can probably pre-assign the IPs as you prefer.

In the Server config file.

ifconfig-pool-persist myClientIPs.txt

will update the file myClientIPs.txt in the /etc/openvpn/server folder as each new client connects. It will re-load the existing list at startup each time. I cannot recall if you need to manually create the file to begin with but I don't believe you do - just ensure the permissions are good.

File contents will look like

DELL10x64.whateverdomain.cc,10.8.1.2,
ANOTHER-PC.whateverdomain.cc,10.8.1.3,
DESKTOP-STANDALONE,10.8.1.4,